I would also like to have an instant message reminder. Windows Live Messenger please! :-)

AIM.

Something interesting: Reqall has a neat integration with AIM. You can add tasks to reqall by sending them an instant message and they can send you feedback like reminders. It even asks you if it is done, if not, it will send a reminder later. This is very cool, and since AIM is using push, even their free version, then the interaction is very cool. Please take a look at this and consider adding something similar to Toodledo. Thanks.

You can add your tasks to Google Calendar as events using Toodledo's iCal subscription: http://www.toodledo.com/connect_ical.php
You cannot edit them on Gcal with the iCal subscription though, which is why people want CalDAV.